FACTORS AFFECTING THE HOMOGENEITY OF READY MIXED CONCRETE

SEVERAL YEARS AGO THE ASTM SPECIFICATIONS FOR READY-MIXED CONCRETE WERE REVISED TO INCLUDE PERFORMANCE CRITERIA FOR WITHIN-BATCH UNIFORMITY. BECAUSE OF THE EXPENSE AND TIME ENTAILED BY THE TESTS, THESE LIMITS HAVE NOT BEEN WIDELY APPLIED TO TRUCK-MIXED CONCRETE. TO DATE, THE WIDEST USE HAS BEEN TO ESTABLISH REQUIRED MIXING TIME IN CENTRAL-MIX PLANTS. THE RESULTS OF THE FIRST YEAR OF A THREE-YEAR RESEARCH PROGRAM ON UNIFORMLY MIXED CONCRETE ARE REPORTED HERE. THE TESTS EMPLOYED WERE DUPLICATE SLUMP, UNIT WEIGHT, AIR CONTENT, COARSE AGGREGATE CONTENT, AND COMPRESSION (6 X 12 INCH SAMPLES). THE VARIABLES WERE SIZE OF BATCH, MIXING REVOLUTIONS, MIXING SPEED, AND LOADINGS. TWO CONDITIONS WERE INVESTIGATED: TWO-STEP LOADINGS AND RIBBON LOADING.

• Supplemental Notes:
  • Rept No 1, 25 PP, 19 FIG, 10 TAB, 8 PHOT, 27 REF
• Corporate Authors:

  Nat Ready Mixed Concrete Association

  ,    
• Authors:
  • Bloem, D L
  • Gaynor, R D
• Publication Date: 1970-6

Subject/Index Terms

• TRT Terms: Concrete mixing; Ready mixed concrete; Specifications; Standardization
• Subject Areas: Construction; Highways; Materials;

Filing Info

• Accession Number: 00215385
• Record Type: Publication
• Files: TRIS
• Created Date: May 10 1971 12:00AM